HD6412240 RENESAS [Renesas Technology Corp], HD6412240 Datasheet - Page 539

• Manufacturer Part Number: HD6412240
• Description: Renesas 16-Bit Single-Chip Microcomputer H8S Family / H8S/2200 Series
• Manufacturer: RENESAS [Renesas Technology Corp]

When performing transfer using the DTC, it is essential to set and enable the DTC before carrying
out SCI setting. For details of the DTC setting procedures, see section 7, Data Transfer Controller
(DTC).
In a receive operation, an RXI interrupt request is generated when the RDRF flag in SSR is set to
1. If the RXI request is designated beforehand as a DTC activation source, the DTC will be
activated by the RXI request, and transfer of the receive data will be carried out. At this time, the
RDRF flag is cleared to 0 if DISEL in DTC is 0 and the transfer counter value is not 0. If DISEL
is 1, or if DISEL is 0 and the transfer counter value is 0, the DTC transfers the receive data but
does not clear the flag. Therefore, the flag should be cleared by the CPU. If an error occurs, an
error flag is set but the RDRF flag is not. Consequently, the DTC is not activated, but instead, an
ERI interrupt request is sent to the CPU. Therefore, the error flag should be cleared.
13.3.7
Switching the Mode
When switching between smart card interface mode and software standby mode, the following
switching procedure should be followed in order to maintain the clock duty.
[1] Set the data register (DR) and data direction register (DDR) corresponding to the SCK pin to
[2] Write 0 to the TE bit and RE bit in the serial control register (SCR) to halt transmit/receive
[3] Write 0 to the CKE0 bit in SCR to halt the clock.
[4] Wait for one serial clock period.
[5] Write H'00 to SMR and SCMR.
[6] Make the transition to the software standby state.
[7] Exit the software standby state.
[8] Set the CKE1 bit in SCR to the value for the fixed output state (current SCK pin state) when
[9] Set smart card interface mode and output the clock. Signal generation is started with the
When changing from smart card interface mode to software standby mode
the value for the fixed output state in software standby mode.
operation. At the same time, set the CKE1 bit to the value for the fixed output state in software
standby mode.
During this interval, clock output is fixed at the specified level, with the duty preserved.
When returning to smart card interface mode from software standby mode
software standby mode is initiated.
normal duty.
Operation in GSM Mode
Rev.3.00 Mar. 26, 2007 Page 497 of 772
Section 13 Smart Card Interface
REJ09B0355-0300